Mortimer dtt perow



(No ModeLj- M. DU PEROW. ELECTRIC SIGNALING APPARATUS.

Patented Aug. 3,1897,

avwewtoz witvwwao K UNITED STATES PATENT EETcE.

MORTIMER DU PEROW, OF WASHINGTON, DISTRICT OF COLUMBIA.

ELECTRIC SIGNALING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 587 ,433, dated August 3, 1897.

Application filed July 10, 1895. Renewed May 1'7, 1897. Serial No. 637,005. (No model.)

To aZZ whom it may concern:

Be it known that I, MORTIMER DU PERo W, a citizen of Canada, residing at Washington, in the District of Columbia, have invented certain new and useful Improvements in Electric Signaling Apparatus; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawing, and to the letters of reference marked thereon, which forms a part of this specification.

My invention relates to signals used in connection with the telephone service; and it consists in the use of two partial signaling-circuits at any station in addition to the telephone speakingcircuit, (including the primary and secondary transmitter -circuits when employed,) one for receiving a signal and having in it a signaling device and the other for transmitting a signal and having in it a source of electricity, said three circuits being independentof each other and being closed at one end into earth or an equivalent return line-wire, their other ends being so arranged as to be closed when required by a single switch connected with the main linewire, and, preferably, the signal-receiving circuit being normally closed by the switch when the telephone is not in use, and the signal-transmitting circuit being normally open and automatically closed by the switch in moving to and fro for the purpose of closing or opening the normally open telephone-circuit.

In the drawing the switch is shown as an ordinary telephone-supporting hook, the contacts are located substantially one above the other, the signal is a bell, there are the usual receiver and transmitter with its so-called local battery, and the source of electricity for the signal-transmittin g circuit is a second battery; and these forms of devices in their by a motor-generator or by the local battery, the contacts be differently placed, and the switch be otherwise located and actuated.

In the drawing the speaking-circuit through the line and earth wires,including the primary and secondary circuits, is indicated by the solid lines. The dotted lines indicate the signal-transmitting circuit, and the dot-anddash lines indicate the signal-receiving circuit.

L is the main-line-wire terminal and E the earth or return wire terminal at any station. When the receiver is removed therefrom, switch hook H closes the primary circuit through contact I, terminal P, the local battery and primary coil of the transmitter, and terminal P. Simultaneously switclrhook I-I closes the secondary circuit through contact J, terminal S, the secondary coil of the transmitter, terminal S, terminal It, the receiver, terminal R, terminal E, the earth, the other instrument, the main line-wire, and termi nal L.

N is the signal-receivin g contact, and M the signal-transmitting contact. M is so located that the switch-hook contacts with it in moving up or down, the persistency of the resulting signal being proportioned to the persistency of the contact. Owing to the form of contact M in the drawing it exhibits an insulated section where the switch-hook rests when the speaking-circuit is in use. Switchhook I-I rests on contact N normallythat is, when the receiver is hanging on the switchhook.

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is-

1. The normally open partial speaking-circuit having in it a telephone, or the primary and secondary coils thereof, and the independent normally open partial signal-transmitting circuit having in it a source of electricity only, in combination with the independent partial signal-receiving circuit having in it a signal and being normally closed by a switch adapted when moved in one direction to successively open the signal-receiving circuit, close and then open the signaltransmittin g circuit, and finally close the speaking-circuit, and when moved back again to reverse these operations, substantially as described.

2. Two telephone-stations joined by a suitable electric circuit, one conductor thereof at each station having three branches, with their respective terminals, said branches having in them respectively a speaking device, a signal-transmittin g device, and a signal-receiving device, and the other conductor at each station being connected to a movable switch adaptedin moving within its prescribed limits to automatically contact with each of said terminals in succession, substantially as described.

3. At atelephone-station,the norm ally open speaking-circuit having in it a telephone and a source of electricity, and the independent normally open signaltransmitting circuit having in it a source of electricity only, in combination with a circuit-changing switch connected to line and adapted when moved in one direction to successively close and then open the signal-transmitting circuit and close the speaking-circuit and when moved back again to successively open the speaking-circuit and close and then open the signal-transmitting circuit, substantially as described.

In testimonywhereof I afiiX my signature in presence of two witnesses.

MORTIMER DU PEROV. WVitnesses:

BEATRICE A. CROGHAN, NATHAN I'I. ROBBINS. 

